U3-1 - Molecular Orbitals Flashcards
How can you tell the number of carbons in this structure?
Count each ‘kink’ on the zigzag, including the ends.
This structure has 7 carbons.
How can you tell how many hydrogens are atached to the circled carbon?
No. of H = 4 – No. of bonds made
This carbon makes 3 bonds, so must have 1 H.
Two atomic orbitals combine to make ___ molecular orbitals.
two
What is the difference between bonding and antibonding orbitals?
Antibonding orbitals are higher in energy.
How do sigma bonds form?
End on overlap of atomic orbitals
How do pi bonds form?
Side on overlap of atomic orbitals.
Which bonds are stronger, sigma or pi?
Sigma (better overlap of atomic orbitals)
How do you count the number of sigma and pi bonds in a molecule?
Single bonds are always sigma.
In double and and triple bonds, first bond is sigma, the rest are pi.
Type of hybridisation found in alkanes
sp3
Type of hybridisation found in alkenes and aromatic rings
sp2
Type of hybridisation found in alkynes (C≡C)
sp
Bond angle associated with sp3 hybridisation
109.5 (tetrahedral)
Bond angle associated with sp2 hybridisation
120 (trigonal planar)
Bond angle associated with sp hybridisation
180 (linear)
Explain how sp3 hybrid orbitals form
One s and three p orbitals mix to form four degenerate sp3 atomic orbitals